Background: High working memory capacity is associated with improved mathematical problem-solving skills. A leading theory about why working memory enhances problem-solving suggests that capable problem solvers might offload information from their working memory for later use. Aims: This study examined whether the ability to offload information improved problem-solving for learners with lower working memory capacity. Sample(s): The participants consisted of 93 undergraduate students from a mid-sized university in the United States. Methods: Participants first took a 10-problem pre-test, followed by working memory tasks. They were then split into two groups: one with the option to offload using paper and pencil and one without. As part of a post-test, they completed 10 math problems. Results: Results indicated that both the offloading and no-offloading groups improved over time; however, the effect was greater for the offloading group, according to Hedges' g. Although no significant interaction between working memory and condition was found, offloading was useful for specific ranges of working memory skills, according to the Johnson-Neyman technique. An interaction analysis of pretest and condition also suggests that offloading may be beneficial with increased prior knowledge. Conclusions: These findings emphasize the importance of considering students' prior knowledge in working memory research. They also demonstrate how external aids influence cognitive processes during problem-solving.